A surgical stapler is a medical device which is used to place surgical staples in a patient to close wounds ranging from bowel resections to skin incisions and others.
The staples to be applied to the tissue must be selected based on the thickness of the tissue to be stapled. Generally, larger staples require the use of surgical staplers that are also larger. For example, one 5 mm stapler sold under the trademark JustRight™, has a nominal shaft diameter of about 5 mm, and is currently indicated for applying staples having a nominal leg length of about 2 mm. Put another way, the 5 mm JustRight™ Surgical Stapler is indicated for use in procedures in which the tissue can be clamped between the stapler jaws to about 1 mm or less. JustRight™ is a trademark belonging to the assignee of this application.
Some currently-available staplers, such as a stapler sold under the trademarks Cardica™ MicroCutter Xchange® 30, do not use staples defined by a leg length; nonetheless, these staplers are similarly limited in that the staplers cannot staple tissue if the tissue cannot be clamped to a certain thickness. Should the surgeon need to staple tissue clamped to, for example, 2 mm, the surgeon would be required to use a stapler that is around 12 mm in diameter.
Some manufacturers have attempted to provide a relatively small stapler that may staple relatively thick tissue, such as the Cardica™ stapler described above. However, these staplers use what are known as D-shaped staples, as illustrated in FIGS. 35A-35B, instead of the more common B-form staples, which are illustrated in FIGS. 35C-35D. The D-shaped staples have relatively thick legs, with one of the legs not having a piercing feature, and have not been subject to extensive field use. It is believed by the Inventors that, for a given tissue thickness, the D-shaped staples introduce more trauma to the patient than do the B-form stapes.
While the use of a larger stapler for placing larger staples is often acceptable, in certain medical procedures, such as in procedures performed on small or weak patients, such as small children or those with physical or disease trauma, it may be desirable to use a relatively small shaft surgical device to staple tissue that is relatively thick, using a B-form staple.
Moreover, it is known that, if a surgeon clamps onto too much tissue for a given staple leg length or indicated use, currently-available staplers could still fire the staples and cut the tissue improperly. That is, the currently-available staplers could fire the staples, and thereafter cut the tissue, leaving the site open. It may therefore be desirable to provide a stapler that does not leave the site open or unsealed if the staples are not properly placed.
It may also be desirable to provide a surgeon the ability to create a wider cuff (that is, a larger tissue margin between the staples and transection line) for a given clamped tissue thickness than is possible using the currently-available surgical devices.
There therefore remains a need for a relatively small surgical stapler capable of stapling relatively thick tissue using B-form staples and/or providing a relatively wider cuff, with less impact to the patient, as well as other new and innovative features.